Fig. 1. Analysis of the vector distributions of a skyrmion^[27]. (a) Mapping from a skyrmion configuration to the unit sphere; (b) transverse vector distribution at given radii of the skyrmions with various values of m and γ

Fig. 2. Diverse forms of skyrmions^[33-34]. (a) Mapping of skyrmions; (b) mapping of bimerons; (c) topological structure with classifications of skyrmion, skyrmionium, bimeron, and bimeronium. In each class, they are also classified by Néel-, Bloch-, and anti-type

Fig. 3. Photonic spin skyrmion in the eOV^[25]. (a) Intensity distribution of the eOV (bottom) and distribution of photonic spin orientation in the centre of the vortex (top); (b) cross section of the energy flux along the radial direction (bottom) and spin vector variation (top)

Fig. 4. Photonic spin texture lattice^[50]. (a) (b) Schematic of the eOV lattice with hexagonal and square symmetry and the distribution of the amplitudes of the resultant Hertz potential; (c) (d) Poynting vector direction (arrows) and magnitude (arrow colors) in the generated eOV lattice with hexagonal and square symmetry, and the background color representing the phase distribution of the total Hertz potential; (e) (f) optical spin orientation distribution of the eOV lattice with hexagonal and square symmetry

Fig. 5. Near-field optical spin scanning system based on a dielectric-nanoparticle-on-film configuration^[25]

Fig. 6. Measurement of the photonic spin in an eOV, the scale bar in Fig.6 (g) is λ/2^[25]. (a)(b) Intensity distribution of RCP and LCP components of light scattered by a nanoparticle with L=1; (c) corresponding spin structure; (d)‒(f) corresponding results with L=0; (g)‒(i) corresponding results with L=-1

Fig. 7. Experimental results of the photonic spin texture lattice, the scale bar in Fig.7(b) and Fig.7(d) is the SPP wavelength^[50]. (a) Near-field optical spin scanning system based on a dielectric-nanoparticle-on-film configuration modulated by the intensity masks with sixfold or fourfold symmetry apertures; (b) (c) measured longitudinal SAM component and reconstructed spin orientation of the skyrmion spin lattice; (d)‒(e) corresponding results of the meron spin lattice

Fig. 8. Measurement of the photonic spin texture of the TE mode^[53]. (a) Schematic of a waveguide structure; (b) schematic of the Ag core and Si shell nanosphere; (c) measured longitudinal SAM component of the single skyrmion, meron, and skyrmion lattice; (d) reconstructed local spin orientation

Fig. 9. Near-field scanning of the electric field skyrmion lattice^[26]. (a) SEM image of the six groups of samples etched with a hexagon on a 200-nm thick Au layer (bottom) and the local unit vector of the electric field (top); (b) real part of the axial electric field at the center of the sample; (c) amplitude of the transverse electric field; (d) vector representation of the transverse electric field; (e) skyrmion number density

Fig. 10. Dynamics of the electric field of the photonic spin texture, the scale bars in Fig.10(c)‒(e) are λ_SPP=530 nm^[54]. (a) Schematic of the PEEM experiment for SPP vortex generation and the SAM texture; (b) SEM image of Archimedean coupling structure etched on an Ag film; (c) static PEEM image of the SPP vortex; (d) time-resolved PEEM images of SPP field amplitude as the delay is advanced from τ to τ+0.9 fs; (e) corresponding FDTD results

Fig. 11. Dynamic imaging of the electric field skyrmion lattice^[57]. (a) 2PPE-PEEM process; (b) excitation of photoelectrons involving a two-photon process and the vector fields in the plane of the SPP; (c) images taken at the same pump-probe delay time (top) and the derived vectors along the dashed line for three relative time delay (bottom); (d) time dependence on the SPP skyrmion lattice

Fig. 12. Photonic skyrmion based on the Stokes parameters. (a) Normalized Stokes parameters in a Poincaré sphere^[59]; (b) mapping of bimeronic beams onto a 3D Poincaré-like sphere, which shows complete transformations among diverse topological textures^[33]; (c) 3D polarization texture of the fully structured light where each Hopf fiber is constructed by a trajectory of a certain polarization ellipse^[60]; (d) conformal frequency conversion of optical skyrmions defined by Stokes vectors^[61]

Fig. 13. Pseudospin texture distribution in the momentum space. (a) Photonic crystal slab with a honeycomb lattice of circular air holes^[64]; (b) band structure near the Dirac points^[64]; (c) pseudospin textures near K and K' points^[64]; (d) photonic crystal with a structure of Kagome and honeycomb lattice of cylinders^[65]; (e) pseudospin textures near the Dirac points^[65]

Fig. 14. Photonic skyrmions in different optical systems. (a) Dynamics of the pseudospin and position of the light beam as it traverses a synthetic magnetization texture^[66]; (b) spatial topological structure of magnetic vector fields for the supertoroidal light pulses^[67]; (c) LSP skyrmions supported by ultrathin space-coiling meta-structures^[68]; (d) device consisting of a microwave resonator with 8-fold symmetry and feeding network and the generated spoof LSP skyrmion^[69]

Fig. 15. Position control of the photonic skyrmion. (a) Schematic of grating structure and the shape and position of the skyrmions, and three SPP standing waves are generated in the center^[76]; (b) dynamic position control of photonic spin skyrmions with the use of a phase profile imposed by a spatial light modulator^[77]

Fig. 16. Interaction between photonic skyrmions and different materials. (a) Schematic of the skyrmion pair with topological charges of opposite-signs and the sensing curve^[78]; (b) schematic of the generation of a photonic skyrmion on the surface of a thin Co film^[80]; (c) schematic of the opposite transverse spins of the coupled surface plasmons and the calculated spin textures^[81]; (d) schematic of dielectric-metal multilayer periodic structures and the skyrmion texture formed in the z=λ plane^[83]